Shrink films, such as shrink sleeves and shrink wraps, are used in labeling, often as an alternative to pressure-sensitive labels, heat-transfer labels, in-mold labels, and other labels. Shrink labeling involves sizing a shrink film, which may be a tubular shrink sleeve, to a particular article. Then one shrinks the film to snugly wrap the article within the shrink sleeve. The shrinking process is generally accomplished by the application of heat or steam to the shrink sleeve. Further processing may include heat-sealing any unsealed portions of the shrink sleeve and/or covering the article contents with a shrink cover. The material used for shrink films, such as a shrink sleeve, may depend on the shape and weight of the article and its contents. The shrink sleeve may be polyethylene terephthalate, polyethylene terephthalate glycol, polyvinyl chloride, or oriented polystyrene, for example. The film has an inherent tension that is released by heating the film from the outside in a shrink oven. Shrink films may be produced in forms that may be oriented monoaxially (in a single direction). As the film cools, it shrinks snugly around the article. This shrinkage applies a very slight pressure to the article, which aids in holding the shrink film to the article.
Graphics, such as pictures, logos, and text for labels, may be reverse-printed on the shrink films and the shrink films then seamed, thereby forming a shrink sleeve. In general, shrink films are reverse-printed using flexographic and rotogravure printing technology. A master roll of shrink film is prepared with a number of label copies across its surface. The particular number of labels depends upon the size of the label copy and the width of the master roll. The printed rolls are then slit-cut, thereby forming individual rolls containing one copy of the label only. The slit rolls are then folded and overlapped, and seamed at the edge, forming a shrink sleeve that is wound on a core. The finished rolls are packaged and delivered to a particular location where each of the shrink sleeves will be applied to an article. These shrink sleeves are commonly used for full body decoration and tamper-evident applications.
When a shrink sleeve is used in tamper-evident applications, perforations may be provided in the shrink film. Generally, these perforations are provided on the shrink sleeve at a position that will be proximal to an opening of the article being labeled. In such a position, a portion of the shrink sleeve above the perforations will contact and confront a closure of the article, and a portion of the shrink sleeve below the perforations will contact and confront a body portion of the article. In use, the closure, such as a cap on a bottle, is removed by applying a twisting or rotating force (i.e., a torsional force) to the closure. As this occurs, the torsional force is also applied to the portion of the shrink sleeve confronting the closure of the article, while not being applied (at least without as much force) to the body portion of the article. As a result, the closure and the portion of the shrink sleeve contacting the closure are removed from the body portion of the article as the tamper-evident portion of the shrink sleeve (i.e., the portion contacting the closure) separates from the remainder of the shrink sleeve along the perforations. It is desirable that the portion of the label below the perforations stay bonded to the article after the consumer opens the article. In order to prevent slippage between the shrink sleeve and the body portion of the article, adhesives may be used to bond the body portion of the shrink sleeve and the body portion of the article to one another.
However, while adhesives may be applied to the portion of the shrink sleeve that contacts the body portion of the article, they are not applied to the portion of the shrink sleeve that contacts the closure of the article (i.e., the tamper-evident portion of the shrink sleeve “above” any perforation). This is because it is desired that the portion of the shrink sleeve confronting the closure be completely separated from the closure and discarded. This prevents any shrink sleeve from remaining on the closure where it could interfere with access to the contents of the article, or interfere with reattachment of the closure to the article.
Further, since the portion of the shrink sleeve that confronts the closure in tamper-evident applications is designed to be separated from both the closure and the remainder of the shrink sleeve, that portion generally is not labeled or otherwise decorated.
While shrink sleeves have been used on closures in tamper-evident applications, other types of materials (nonshrink films) have been used on closures for purposes other than temper-evident applications. For example, pressure-sensitive labels have been positioned on the “land” (i.e., the top) of closures, such as caps for bottles. These labels may include decorations and/or labels. However, labels, such as the decorated pressure-sensitive labels, have not been applied to the sides of closures for various reasons. One reason is that the side surfaces of closures often include features like ridges or flanges that disrupt the ability of the label to adhere to, or otherwise associate with, the side of the closure, and also may interfere with the presentation of any decoration. Further, any label, such as the shrink sleeves described above, is easily separated from the closure due to the torsional forces applied when removing the closure from the container body. Thus, any label information is lost. Further, the appearance of an article having a label or other decoration removed due to these torsional forces may be unaesthetic.
In view of the above, it would be desirable to provide a decorated closure for an article having a shrink sleeve label that is associated with the side surface of the closure. Further, it would be desirable for the shrink sleeve to have decorations that are visible and intelligible (even on irregularly-shaped closures). It would be further desirable that such a decoration be impervious to torsional forces applied to the closure during use.